JPH026961A - Photosensitive body - Google Patents

Abstract

PURPOSE:To improve durability by forming a surface protective layer into two-layered constitution consisting of a thin metal compd. film layer and the extreme surface protective layer consisting of an a-C film. CONSTITUTION:This photosensitive body has the surface protective layer 4 of the two layers; the thin metal compd. film layer 1b formed by any of a vacuum vapor deposition method, sputtering method or ion plating method and the extreme surface layer 1a consisting of the amorphous hydrocarbon film (a-C film) formed by a plasma polymn. method on this thin metal compd. film layer 1b. The extreme surface layer 1a having the advantages such as adequate electrostatic chargeability, light transmittability and hardness possessed by the a-C layer 1a while maintaining the functions of a photoconductive layer is formed by providing the thin metal compd. film layer 1b between the photosensitive layer 2 and the a-C layer 1a in such a manner. The extreme surface layer 1a is formed to 0.01-5mum thickness. The durability is improved in this way.

Description

[Detailed description of the invention] The present invention relates to an organic photoreceptor having a surface protective layer.

Prior Art and Problems In recent years, electrophotographic photoreceptors in which an organic photoconductive material is blended with a binder resin have come into wide use.

This type of photoreceptor has the advantage of being excellent in industrial productivity in that selenium, cadmium sulfide, etc. are easily processed.

However, these organic photoreceptors lack hardness and are easily scratched and scratched by friction from transfer paper, cleaning members, developers, etc. during repeated use.

Therefore, in order to solve such problems, is there any proposed technology for providing a surface protective layer on the surface of the organic photoreceptor? What is fundamentally important for the surface protective layer is the provision of a surface protective layer. The purpose is to avoid deterioration of the photoreceptor characteristics due to the above.

As a type of surface protective layer, a plasma polymerized film of an appropriate organic compound is considered (for example, Japanese Patent Application Laid-Open No. 60-320
When plasma polymerization is performed on the surface of the organic photosensitive layer (No. 55, etc.), the photocharge-generating substance or charge-transporting substance contained in the organic photosensitive layer is degraded by the plasma, and the photoreceptor properties deteriorate instead. There is a problem with becoming.

That is, by plasma polymerization, the structure near the surface of the organic photosensitive layer is destroyed by electron or ion bombardment,
When the surface of the organic photosensitive layer is a charge transport layer, the transport property of the layer near the surface is reduced, leading to the generation of residual potential, and when the surface of the organic photosensitive layer is a charge generation layer, the charge generation ability is reduced, Sensitivity decreases to the point where it almost disappears. In the case of a single-layer structure in which a charge-generating material and a charge-transporting material coexist, the above-mentioned deterioration occurs in combination.

Problems to be Solved by the Invention The present invention solves the above-mentioned problems and provides a plasma that has excellent durability and sufficiently satisfactory photoreceptor characteristics (especially sensitivity, residual potential, etc.) to function as a photoreceptor. An object of the present invention is to provide an organic photoreceptor having a polymer film as a surface protective layer.

Means for Solving the Problems The present invention provides a photoreceptor having an organic photosensitive layer (2) on a conductive support (3), in which a vacuum evaporation method, a sputtering method or an ion plating method is applied on the surface of the photosensitive layer. a metal compound thin film layer (I b) formed by any of the methods described above, and an outermost surface layer (l
The present invention relates to a photoreceptor characterized in that it has a surface protective layer (4) consisting of the two layers of a).

The photosensitive layer (2) consists of a known organic photoreceptor and a conductive substrate (
3) The internal structure of the photosensitive layer (2) is a photosensitive layer with a single-layer structure in which a photoconductive material and a charge transporting material are blended as a binder on a conductive substrate; The photosensitive layer may have a structure in which a charge generation layer and a charge transport layer are sequentially formed on a support, or a structure in which a charge transport layer and a charge generation layer are sequentially formed on a conductive support. .

Several mechanical photoreceptors having the above-mentioned organic photosensitive layer are well known (for example, NIKKEI NEW MATERI).
ALS December 15, 1986 issue, pages 83-98
It is a photoreceptor with excellent sensitivity, charging ability, and manufacturing cost, and has been put into practical use.

In general, materials used for producing organic photosensitive layers include:
Examples of photoconductive materials that contribute to charge generation include phthalocyanine pigments, azo pigments, and perylene pigments, and examples of charge transport materials that contribute to charge transport include triphenylmethane compounds and triphenylamine. compounds, hydrazone compounds, styryl compounds, pyrazoline compounds, oxazole compounds, oxadiazole compounds, etc. are used, and as binding materials for dispersing and coating these, for example, polyester, polyvinyl butyral, polycarbonate, polyarylate, phenoxy, styrene. Resin such as acrylic is used.

The conductive substrate (3) may be any material as long as at least its outermost surface is conductive, and may have any shape such as a cylindrical shape, a visible belt shape, or a flat plate shape.

When the metal compound thin film layer (I b) is later formed as the outermost surface layer (la) by plasma polymerization, the photoconductive layer (2) is deteriorated by the plasma, and the photoreceptor characteristics such as residual potential and sensitivity are deteriorated. It plays the role of protecting the organic photosensitive layer from deterioration, and also works to improve the adhesion between the organic photosensitive layer and the outermost layer that will be formed later.

The metal compound thin film layer does not undergo deterioration due to plasma, and when irradiated with light, the light can pass through the layer and reach the photosensitive layer, and it also receives injection of charges generated in the photosensitive layer. It is necessary that it does not interfere with the neutralization and disappearance of surface charges.

These metal compound materials include 5iO1Si02, T
iO2, S i C, MgO, MgF2, T10, Nb
2O,,5n02,ZnO,S i )N,,A203
, Z r O2, Ta2O, etc., but preferred are Sin, At□03, and MgO.

Examples include Nb2O, etc.

The metal compound thin film layer can be easily formed into a thin film with a uniform thickness using a vacuum evaporation method, a sputtering method, or an ion plating method using a known device.

It is preferable that the metal compound thin film layer be formed as thinly as possible to impart the function aimed at by the present invention to the core layer.
The film is formed to have a thickness of 3 μm or less, more preferably 0.1 to 2 μm. When the film thickness is less than 0.1 m, it is difficult to form a uniform thin film, and when the film is thicker than 2 μm, problems such as deterioration of light transmittance and increase in volume resistance arise.

The outermost surface layer (1a) made of the a-C film itself has suitable charging ability, has excellent translucency, and is a scratch-resistant film with a high hardness of about 4a. If provided, as mentioned above, the organic photosensitive layer will suffer plasma damage,
Problems arise in which the characteristics of the photoreceptor deteriorate, such as a decrease in sensitivity and an increase in residual potential.However, by providing the metal compound thin film layer between the photosensitive layer and the a-C layer according to the present invention, the function of the leading 7jL layer can be maintained. Therefore, the preferred charging ability of the a-C layer,
It becomes possible to form an outermost layer having advantages such as translucency and hardness.

The amount of hydrogen atoms contained in the a-C film is not particularly limited, or is necessarily limited by the structure of the surface protective layer and the production aspect of glow discharge, and the amount is approximately 5 to 60 atm.
ic% (hereinafter abbreviated as "ratm").

The amount of carbon atoms and hydrogen atoms contained in the a-C film can be determined by means such as organic elemental analysis, Auger analysis, and SIMS analysis.

The outermost layer (1a) of the present invention has a thickness of 0.01 to 5 μm,
Preferably 0.05 to 2 μm1, more preferably 0
．． It is formed to a thickness of 1 to lpm.

If it is thinner than 0.012 m, the film strength will decrease and it will be easily scratched. Further, if the thickness is more than 5 μm, the light transmittance is reduced, and the irradiated light cannot be effectively guided into the photosensitive layer, resulting in a decrease in sensitivity.

The outermost layer (1a) is formed by a glow discharge plasma method. The outermost layer (1a) discharges molecules containing at least carbon atoms and hydrogen atoms in a gas phase under reduced pressure, and diffuses active neutral species or charged species contained in the generated plasma atmosphere onto the substrate, applying electric force. Alternatively, it is induced by magnetic force, etc., and deposited as a solid phase through a recombination reaction on the substrate.
So-called plasma reaction (hereinafter referred to as P-CVD reaction)
By doing a-CrI! It can be formed as X.

Each of the above-mentioned molecules does not necessarily have to be in a gas phase at normal temperature and pressure, and can be used in either a liquid phase or a solid phase as long as it can be vaporized through melting, evaporation, sublimation, etc. by heating or reduced pressure.

As molecules containing at least carbon atoms and hydrogen atoms, hydrocarbons such as saturated hydrocarbons, unsaturated hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, etc. can be used.

Examples of saturated hydrocarbons include methane, ethane, propane, butane, pentane, hexane, heptane, octane, isobutane, impentane, neopentane, inhexane, neohexane, dimethylbutane, methylhexane, ethylpentane, and methylbentane. , tributan,
Methylhebutane, dimethylhexane, trimethylpentane, isonanone, etc. can be used.

Examples of unsaturated hydrocarbons include ethylene, propylene, imbutylene, butene, pentene, methylbutene,
hexene, tetramethylethylene, heptene, octene, allene, methylalene, butadiene, pentagene,
Hexadiene, cyclopentanene, ocimene, aronmene, myrcene, hexatriene, acetylene, methylacetylene, butyne, pentyne, hequinene, heptyne,
Octyne, butadiyne, etc. can be used.

Examples of alicyclic hydrocarbons include cyclopropane, cyclobutane, cyclobentane, cyclohexane, cyclohebutane, cyclooctane, cyclopropene, cyclobutene, cyclopentene, /chlorhexene, cycloheptene, cyclooctene, limonene, terhyrune, phelandrene, and nlubes!・En, Tsuen, Caren, Bi, N, Polniene, Kanghuen, Fuenchen, cyclobutene, tricyclene, pisapoene, zingibene,
Curcumene, humulene, cadinosekibenichen, serimene, caryophyllene, santarene, cedrene, camphoene, phylloclatene, photocarprene, mien, and the like can be used.

Examples of aromatic hydrocarbons include benzene, toluene, quinene, hemimelithene, pseudocumene, menthiene, prenitene, indulene, durene, pentamethylbenzene, hexamethylbenzene, ethylbenzene,
Flobylbenzene, methane, styrene, hiphenyl, terphenyl, diphenylmethane, triphenylmethane,
Dibenzyl, stilbene, indene, naphthalene, tetralin, anthracene, phenanthrene, etc. can be used.

In particular, compounds having unsaturated bonds are highly reactive and are therefore preferred in terms of producing a high-quality film. Among these, butane and propylene are particularly preferred in terms of film-forming properties, ease of handling residue, and cost.

The amount of hydrogen atoms contained in the a-C film changes depending on the form of the film forming apparatus and the conditions during film forming.If the hydrogen amount is low, for example, the temperature of the substrate may be increased or the pressure may be lowered. , lower the dilution rate of the raw material hydrocarbon gas, use a raw material gas with a lower hydrogen content, increase the applied power, lower the frequency of the alternating electric field, increase the strength of the DC electric field superimposed on the alternating electric field. , etc. may be mentioned.

FIGS. 2 and 3 are diagrams showing an example of a glow discharge decomposition apparatus for forming the outermost surface layer of the present invention. Figure 2 shows a parallel plate type P-CVD device, Figure 3 shows a cylindrical type 1”-CVD device.
D device is shown.

First, explanation will be given using FIG. 2.

In Fig. 2, (701) to (706) are the first tubes in which the raw material compounds and carrier gas, which are in the gas phase at room temperature, are sealed.
Each tank is connected to the first to sixth control valves (707) to (712) and the first to sixth flow rate controllers (713) to (718).

Hydrogen gas, argon gas, helium gas, etc. can be used as the carrier gas.

In the figure, (719) to (721) are first to third containers filled with raw material compounds that are in a liquid or solid phase at room temperature, and each container is connected to a first to third heater (722) for vaporization. ) to (724), and each container can be heated by seventh to ninth control valves (725) to (72
7) and seventh to ninth flow rate controllers (728) to (730)
)It is connected to the.

These gases are mixed in a mixer (731) and then sent into a reaction chamber (733) via a main pipe (732).

The pipes along the way can be heated by a pipe heater (734) that is appropriately placed to prevent condensation of raw material compounds or vaporized gases that are in a liquid or solid state at room temperature. .

Inside the reaction chamber, there is a ground electrode (735) and a power application electrode (73).
6) are installed facing each other (7), and each electrode is equipped with an electrode heater (7).
737), it is possible to provide heat.

The power application electrode (736) is equipped with a matching box for high frequency power (7
A high frequency power supply (739) is connected through a high frequency power supply (739) through a low frequency power matching box (740), a low frequency power supply (741) is connected through a low pass filter (742), and a DC power supply (743) is connected through a low pass filter (742). The selection switch (744) selects power with different frequencies, for example, frequencies from IKHz to 100KHz.
0Kf (Z low frequency power, or 1.3.56MHz
It is possible to apply high-frequency power, etc. Furthermore, it is also possible to superimpose DC power.

The pressure inside the reaction chamber (733) can be adjusted by a pressure control valve (745), and the pressure inside the reaction chamber (733) can be reduced through an exhaust system selection valve (746) by a diffusion pump (747),
Oil rotary pump (748) or cooling exclusion device t (
749), a mechanical booster pump (750), and an oil rotary pump (748).

The exhaust gas is further rendered safe and harmless by an appropriate exclusion device (753) before being exhausted into the atmosphere.

For these exhaust system piping, appropriately placed piping heaters (734
), it is said that heating is possible.

The reaction chamber (733) is also equipped with a reaction chamber heater (75) for the same reason.
1) allows heating, and a substrate (752) is placed on an electrode arranged inside.

Whether or not to install these heaters can be selected depending on the properties of the raw material gas used, but in particular organic materials with a boiling point of 150°C to +15°C under normal pressure are In the case of using a compound, it is often unnecessary, which is preferable because it allows the production equipment to be simplified.

Generally, when an organic compound with a boiling point lower than 150°C is used as a raw material gas, in order to prevent the generation of fine powder polymer inside the reaction chamber (733), the boiling point must be lowered to +15°C.
When higher organic compounds are used as raw material gas,
In order to prevent condensation within each type of piping, it is desirable to provide various types of heaters as described above.

In FIG. 2, the substrate (752) is fixed to the ground electrode (735), but it may be fixed to the power application electrode (736), or may be fixed to both.

The apparatus shown in FIG. 3 is basically the same as the apparatus shown in FIG.
) or cylindrical. The substrate (752) also serves as a ground electrode (735), and both the power application electrode (736) and electrode heater (737) have a cylindrical shape. Also, the board (752) is capable of self-reflection using an external drive motor (not shown).

In the above configuration, the pressure in the reaction chamber used for producing the photoreceptor is previously reduced to about lo-4 to to-6 Torr by a diffusion pump, and the vacuum degree is checked and the residue adsorbed inside the apparatus is removed.

At the same time, the electrode and the substrate fixedly disposed on the electrode are heated to a predetermined temperature by the electrode heater.

As the substrate, a photoreceptor is used in which a thin film layer of a metal compound is provided on a known organic photosensitive layer on a Tt conductive substrate. At this time, the substrate temperature is preferably set to about 100° C. or less in order to prevent thermal denaturation of the organic photosensitive layer.

Next, the first to sixth tanks i are filled with the first to third tanks.
The raw material waste from the container is introduced into the reaction chamber after being made into a constant flow rate using the first to ninth flow rate controllers, and the pressure inside the reaction chamber is adjusted to approximately 0.05 Torr to 5.0'For by using the pressure regulating valve.
Maintain a reduced pressure of about r.

The waste flow rate is stabilized by J-vortex and connection selection switch.
For example, a low frequency power source is selected and low frequency power is applied to the power application electrode.

A discharge is started between the two electrodes, and over time a solid phase organic plasma polymerized film is formed on the substrate.

The membrane volume rate is 10 persons/min to 3 μm/min, preferably 10
0 people/min to ltim/min, more preferably 500 people/min
Preferably, the speed is from 50,008 minutes to 50,008 minutes. If the film deposition rate is lower than IO people/min, it is unfavorable in terms of productivity. If the film deposition rate is higher than 3 μm/min, film roughness tends to occur, and a homogeneous film is not necessarily obtained, which is not preferable.

When a predetermined film thickness is reached, the discharge is stopped, and a photoreceptor having the a-C film according to the present invention as the outermost layer is obtained.

The outermost layer a-C film of the present invention contains heteroatoms other than carbon and hydrogen, such as fluorine, chlorine, bromine, or iodine atoms, oxygen atoms, nitrogen atoms, and periodic atoms as conductivity-dominant substances. Group Ⅰ elements of the Table of Contents (B, AI, Ga, In,
etc.), Group V elements of the periodic table (P, AS, sl), etc.) may be included.

Introducing halogen; . Such an effect is particularly large when seven elementary atoms are introduced.

The introduction of oxygen or nitrogen atoms has been found to be effective in improving moisture resistance. This is because the weak bonds are forcibly broken during the reaction, filling in the gaps between them, forming strong bonds between nitrogen/carbon atoms and between oxygen/carbon atoms, and as a result, inhibiting the adhesion of moisture. It is thought that

The addition of group V and group II elements makes the surface side relatively N-type (
(group ■ element), P-type (group ■ element) 3
By doing so, the reverse 7) Iass effect can be brought about, and improvements in charging ability, reduction in dark decay, and improvement in sensitivity can be achieved.

Addition of group (2) elements has the effect of cutting harmful short wavelength light, and is effective for organic photoreceptors that are prone to optical fatigue.

A plurality of these heteroatoms may be used, or depending on the purpose, they may be mixed only at specific positions in the a-C outermost layer, or they may have a concentration distribution.

In order to mix heteroatoms such as halogen atoms, oxygen atoms, nitrogen atoms, elements of group Ⅰ of the periodic table, elements of group Ⅰ of the periodic table, or elements of group V of the periodic table into the a-C film, these a suitable gaseous compound containing the elements together with a hydrocarbon gas,
The film may be formed in a plasma state. Of course, the phase state of these compounds does not necessarily have to be a gas phase at room temperature and pressure; they can be used in either a liquid or solid phase as long as they can be vaporized through melting, evaporation, sublimation, etc. by heating or reduced pressure. It is.

For molecules containing at least a halogen atom, for example,
Fluorine, chlorine, bromine, iodine, hydrogen heptadide, hydrogen chloride,
Hydrogen bromide, hydrogen iodide, methyl fluoride, methyl chloride, methyl bromide, methyl iodide, ethyl fluoride, propyl fluoride, butyl fluoride, amyl heptaconide, fluorobenzene,
Chlorbenzene, fluorostyrene, fluoroform,
Chloroform, carbon tetrafluoride, vinylidene fluoride, perfluoroethylene, perfluoropropane, etc. can be used.

Examples of molecules containing at least an oxygen atom include oxygen, water vapor, nitrous oxide, carbon oxide, carbon dioxide, methanol formaldehyde, acetaldehyde, formic acid, acetic acid, acetone, ethyl methyl ketone, methyl ether, ethyl ether, Propyl ether, vinyl ether, a-ethene, dioxane, ethyl formate, methyl acetate, 7ran, oxasol, etc. can be used. A plurality of these molecules may be used.

Examples of molecules containing at least a nitrogen atom include nitrogen, ammonia, nitrous oxide, nitrogen oxide, nitrogen dioxide,
Methylamine, ethylamine, hydrazine, aniline,
Methylaniline, toluidine, benzylamine, ethylenediamine, acetonitrile, pyrooxazole, thiazole, imidazole, pyridine, oxazi>・
, carbazole, phenanthridine, imidazothiazole, etc. can be used.

Examples of molecules containing at least Group Ⅰ elements of the periodic table include B2H6, BCi23, BBr, BF, B(
OC2H5)3, /1c123, A+1(CH3)II
, A12(OiC3H?)3, Ga(CzHs)3, I
n(C2)(S)1 etc. can be used.

As a compound containing at least an element of group Ⅰ of the periodic table,
For example, SiHS1□H, (C2H5)3SiH1
SiF 5iHzC1z, 512F2H2, 5iC1,
,S i(OCH3)4,S i(OC2H,),,S
i(OC3Ha)1,GeH,,GeC1GeF,
,Ge,H,,Ge(QCHl)1,Ge(OC2H6
)4% Ge(C2+(S)4, (CH3), Sn
, S n(○CH,)i(C2H,)4 S n,
It is also possible to use S nCtt or the like.

Examples of molecules containing at least Group V elements of the periodic table include PH, PF, PF, and P (12F).

PC02F,, PCQ3, PBr3, P O(OCt(
3) 3,P(C2H5)3,POCQ,,AsH,,A
sCQ3, AsBr, , AsF, , AsF 5, AsC
Q,,SbH,,5bF1.5bC12x,5b(OC
zHs)x etc. can be used.

The amount of the heteroatoms contained in the a-C film can be adjusted by increasing or decreasing the amount of molecules containing heteroatoms used in the plasma CVD reaction. In order to make the amount of heteroatoms contained in the a-C film non-uniformly distributed in the depth direction of the a-C film, it is necessary to adjust the amount by increasing or decreasing the amount of molecules containing heteroatoms during the plasma CVD reaction. Bye.

Here, the effect of the addition of heteroatoms appears at O, latm, % or more. The upper limit is not particularly limited and is necessarily determined by the raw materials used and the production method called the Gu I Fu discharge method.

The content of the above-mentioned heteroatoms can be determined by means such as Auger analysis and organic elemental analysis.

Residue ■ Natanylphthalonanine (TiOPc) was vacuum-deposited using a resistance heating method at a port temperature of 400°C to 500°C and a vacuum degree of 10-' to 10-'' Torr.
A TiOPc vapor-deposited film having a thickness of 2500 mm was formed as a charge generation layer on a cylindrical aluminum substrate having a diameter of 80 mm and a length of 330 mm.

Next, 1 part by weight of p-bisdiethylaminotetraphenylbutadiene (described in JP-A No. 62-30255) and polycarbonate (-1300 manufactured by Teijin Kasei) were added.
) is dissolved in 6 parts by weight of TI-(F), and this solution is applied onto the charge generation layer to a dry film thickness of 15 μm, dried to form a charge transport layer, and an organic photosensitive layer is formed. formed a layer.

Furthermore, SiO was deposited on this photosensitive layer under a vacuum of I.times.10-'Torr to form a metal compound thin film layer having a thickness of 3500 mm.

Finally, a surface protective layer made of an organic plasma polymerized film was formed using the plasma polymerization apparatus shown in FIG. 3 under the conditions described below.

Gas used: Hydrogen 300 secm Butadiene losccm Carbon tetrafluoride 10105e Film forming conditions: Pressure Q, 3 Torr power supply; Low frequency power frequency 30 KHz Power 350 W Substrate temperature 70°C Film forming time 10 minutes Film thickness 10008 rated photoreceptor The electrostatic properties, printing durability test, and electrostatic properties after the printing durability test were evaluated.

The electrostatic properties can be determined by using a laser optical system (wavelength 780 nm) as a light source.
) using an electronic copying machine (EP-14702 (manufactured by Minolta Camera)), and transferred the obtained photoreceptor to the above-mentioned copying machine E.
The initial surface potential (V,) when mounted on the P-4702 and corona charged at -6.2 KV, and the exposure amount E1/2 (erg/c) required to completely reduce the initial surface potential by half.
m2), and the residual potential Vr when irradiated with a Haloken lamp with a color temperature of 2200° at 60 (1ux-sec)
(V) was measured.

The printing durability test was conducted using the above EP-4702 at an initial printing speed of 500 ml.
0 pieces, 7000 pieces, 10000 pieces, 20000 pieces, 40
000 sheets, 50000 sheets, 70000 sheets, toooooo
The image quality after printing was evaluated. The image quality is "O" if a good image is obtained without any loss of density or fogging.
, "△" indicates a decrease in density or occurrence of fog, and "△" indicates a significant decrease in density or occurrence of fog.
It was evaluated as "X".

After the printing durability test, check the electrostatic properties again ■. , E1/2, ■'' were measured in the same manner as above.

The above results are shown in Table 1.

1 part by weight of a styryl compound of the following structural formula [■] and 1 part by weight of a polycarbonate resin (manufactured by Yondai Kasei Co., Ltd. -1300) were placed on a cylindrical aluminum substrate with a major diameter of 80 mm x a length of 330 mm, and 1 part by weight of dichloromethane.
The solution dissolved in 0 parts by weight was dried to a film thickness of 15 μm.
A charge transport layer was formed by coating and drying.

Next, 5 parts by weight of the anthanthrone compound having the following structural formula [1], 1 part by weight the styryl compound having the above structural formula [11], and a polycarpo fu-1 resin (Ni-1300, manufactured by Yadai Kasei Co., Ltd.) were mixed in a ball mill. 24
A dispersion solution prepared by time dispersion was applied onto the charge transport layer by dipping to a dry film thickness of 5 μm to form a charge generation layer.

In addition, A
1□0. A metal compound thin film layer with a thickness of 2000 mm was formed by ion plating.

Finally, a surface protective layer made of an organic plasma polymerized film was formed using the plasma polymerization apparatus shown in FIG. 3 under the conditions described below.

Gas used: Hydrogen 300 secm Propylene 1Qsccm Perfluoro 70 pyrene 5 sec Film forming conditions: Pressure Q, 25 Torr power supply; High frequency power supply frequency 13.56 MHz Power 150 W Substrate temperature 50°C Film forming time 15 minutes Film thickness 2000 A Evaluation obtained The electrostatic properties of the photoreceptor, the printing durability test, and the electrostatic properties after the printing durability test were evaluated.

The electrostatic properties were measured using an electronic copying machine (EP-4702 (manufactured by Minolta Camera)) modified to reverse the polarity of the charged developer, and the resulting photoreceptor was mounted on the above-mentioned copying machine EP-4702, and +6. The initial surface potential (VO) when charged with corona at 5 KV, the exposure amount E 1/2 (f2ux-see) required to halve the initial surface potential, and the halogen lamp with a color temperature of 2800° at 60 [ 1ux-s
ec] The residual potential Vr (V) upon irradiation was measured.

The printing durability test was conducted using the above EP-4702 at an initial printing speed of 500 ml.
0 pieces, 7000 pieces, 10000 pieces, 20000 pieces, 40
000 pieces, 50000 pieces, 70000 pieces, 100000 pieces
The image quality after printing was evaluated. The image quality is determined as rOJ when a good image is obtained without any decrease in density or fogging.
, "△" indicates a decrease in density or fogging, and "△" indicates a significant decrease in density or occurrence of fogging.
It was evaluated as "x".

After the printing durability test, the electrostatic characteristics were checked again. , El/2, and V'' were determined 6111 in the same manner as above.

The above results are shown in Table 1.

Example 3 25 parts by weight of special α-type copper phthalonanine (manufactured by Toyo Ink Co., Ltd.), 50 parts by weight of acrylic melamine thermosetting resin (mixture of A-405 and Superbe/Kamin J820, manufactured by Inu Nippon Ink Co., Ltd.)
A mixture of 25 parts by weight of 4-diethylaminobenzaldehyde-diphenylhydrogen 9 fufu and 500 parts by weight of a solvent (a mixture of 7 parts by weight of quince and 3 parts by weight of butanol) was pulverized and dispersed in a ball mill for 10 hours. This dispersion was applied onto a cylindrical aluminum substrate with a diameter of 60 mm and a length of 290 mm using a spray method so that the film thickness after drying and baking would be 15 μm, and baked at +50°C for 1 hour to form an organic photosensitive layer. Formed.

Then, MgO was sputtered at a vacuum level of 1 x 1 O-'Torr to form a metal compound thin film layer with a thickness of 1500 mm.

Finally, a surface protective layer consisting of an organic plasma polymerized film was formed using the plasma polymerization apparatus shown in FIG. 3 under the conditions described below.

Gas used: Hydrogen 250 secm Butadiene 60 secm Carbon tetrafluoride 60 sec Film forming conditions: Pressure 0.4 Torr power; Low frequency power frequency 60 KHz Power 200 W Substrate temperature 100°C Film forming time 6 minutes Film thickness 200 people evaluated The electrostatic properties of the photoreceptor, the printing durability test, and the electrostatic properties after the printing durability test were evaluated.

The electrostatic properties were measured using an electronic copying machine (EP-3502 (manufactured by Minolta Camera)), and the obtained photoreceptor was tested using the above-mentioned copying machine EP-3502.
The initial surface potential (VO) when mounted on the 3502 and corona charged at +6.5 KV, the exposure amount E1/2 (12ux-sec) required to halve the initial surface potential,
and a halogen lamp with a color temperature of 2800°.
The residual potential Vr (V) when irradiated with 1ux-sec was measured.

The printing durability test was conducted using the above EP-3502 at an initial printing speed of 500 ml.
0 pieces, 7000 pieces, 10000 pieces, 20000 pieces, 40
000 sheets, 50000 sheets, 70000 sheets, toooooo
The image quality after printing was evaluated. The image quality is evaluated as "○" if one good image is obtained without any loss of density or fogging.
”, “△” indicates a decrease in density or blurring occurs,
Cases where there was a significant decrease in density or significant fogging were rated as "x".

After the printing durability test, the electrostatic characteristics were checked again. , El, /2, and Vr were measured in the same manner as above.

The above results are shown in Table 1.

Comparative Example I A photoreceptor was prepared in the same manner as in Example 1 except that the metal compound thin film layer and the surface protective layer were not formed on the charge transport layer.

Evaluation was performed in the same manner as in Example 1.

The results are shown in Table 1.

Comparative Example 2 A photoreceptor was prepared in the same manner as in Example 2 except that the metal compound thin film layer and the surface protective layer were not formed on the charge generation layer.

Evaluation was performed in the same manner as in Example 2.

The results are shown in Table 1.

Comparative Example 3 A photoreceptor was prepared in the same manner as in Example 3, except that the metal compound thin film layer and the surface protective layer were not formed on the photosensitive layer.

Evaluation was performed in the same manner as in Example 3.

The results are shown in Table 1.

Comparative Example 4 A photoreceptor was prepared in the same manner as in Example 1 except that the metal compound thin film layer was not formed on the charge transport layer in Example 1.

Evaluation was performed in the same manner as in Example 1.

The results are shown in Table 1.

Comparative Example 5 A photoreceptor was prepared in the same manner as in Example 2 except that the metal compound thin film layer was not formed on the charge generation layer.

Evaluation was performed in the same manner as in Example 2.

The results are shown in Table 1.

Comparative Example 6 A photoreceptor was prepared in the same manner as in Example 3, except that the metal compound thin film layer was not formed on the photoreceptor layer in Example 3.
7.

Evaluation was performed in the same manner as in Example 3.

The results are shown in Table 1.

Effects of the Invention According to the present invention, the surface protective layer of an organic photoreceptor having an organic photoconductive layer has a two-layer structure consisting of a metal compound thin film layer and an a-C film as the outermost surface protective layer. The conductive photoreceptor properties, particularly sensitivity, residual potential, etc., are not impaired and the durability is excellent.

[Brief explanation of the drawing]

Figure m1 shows a schematic cross-sectional view of the photoreceptor. FIGS. 2 and 3 show an example of an apparatus for producing the outermost surface layer of a photoreceptor according to the present invention. The symbols in the figure are as follows. (1a)... Outermost surface layer (1b)... Metal compound thin film layer (2)... Photosensitive layer (3)... Conductive substrate (4)... Surface protective layer (701) to (706) )... Tanks (707) to (712)... Control valves (713) to (718)... Flow rate controller (728) to
(730)...Flow rate controller (719) to (721).
... Containers (722) to (724) ... Heater (731) ... Mixer (732) ... Main pipe (733) ... Reaction chamber (734) ... Piping heater (736) ...Power application electrode (737)...Electrode heater (738)...High frequency power matching box (739)...High frequency power source (740)...Low frequency power matching box (741)... ...Low frequency power supply (742) ...Low pass filter (743) ...DC power supply (744) ...Connection selection switch (745) ...Pressure control valve (746) ...Exhaust system selection valve ( 747) Diffusion pump (748) Oil rotary pump (749) Cooling exclusion device (750) Mechanical booster pump (751
)...Reaction chamber heater (752)...Substrate (753)...Exclusion device Figure 1 Patent applicant Minolta Camera Co., Ltd.

Claims (1)

[Claims] 1. In a photoreceptor having an organic photosensitive layer (2) on a conductive support (3), a metal formed on the surface of the photosensitive layer by either a vacuum evaporation method, a sputtering method, or an ion plating method. A surface protective layer consisting of two layers: a compound thin film layer (1b) and an outermost surface layer (1a) consisting of an amorphous hydrocarbon film (a-C film) produced by plasma polymerization on the metal compound thin film layer ( 4) A photoreceptor characterized by having the following.